1. Field of the Invention
The present invention relates to a head-up display device, for a vehicle, that provides a driver with information through a virtual image projected on a combiner, front windshield or the like in a driver's direct line of sight.
2. Description of the Related Art
A conventional head-up display device for vehicles is disclosed in Japanese Patent Application Laying-Open publication No. 2001-357498. This conventional head-up display device includes an obstacle detecting means for detecting an obstacle in front of a driver, a regard point detecting means for detecting a point of regard of the driver, a projector for projecting a virtual display image representing various information to a driver, and a display changing means for changing the information represented by the virtual display image according to the movement of the point of regard and also for changing a size of a display area according to a vehicle running environment and a driver's skill.
The above known conventional head-up display device, however, encounters a problem in that it is difficult for a driver to early become aware of the virtual display image, especially a warning display image, produced by the head-up display device when the driver looks away considerably from his or her usual forward viewpoint while the driver drives, in order to operate a switch of an on-vehicle device, such as a mirror-angle adjustment switch provided on a driver's door, which is distant from the usual forward viewpoint, because positions of the display virtual image and the display area are fixed to be accommodated to the usual forward viewpoint.
It is, therefore, an object of the present invention to provide a head-up display device, for a vehicle, which overcomes the foregoing drawbacks and can help a driver recognize a display image representing information produced by a head-up display device earlier when the driver operates an on-vehicle device.